Pochettino said: "I feel disappointed, I feel really bad. I don't feel great. The performance was not good. We started the game not in the way we were supposed to start. We conceded a goal so easily, we made things easy for Arsenal.
"I think after 10 or 15 minutes, after we concede, in this moment we started to play a little bit, we started to create some chances. We were talking at half-time, it is not possible to start the game like this, but we started in a bad way again conceding two goals in this moment, I think the team gave up and we were not in the game.
"It's difficult to talk because we are talking after nearly one season in the same way. It's impossible to see after Saturday at Wembley, a fantastic performance, competed really well against a very good team like Manchester City and then today.
"You can lose against Arsenal, they are fighting for the Premier League, but in the way we competed. Why one day, three days ago, and then today in this way? For the circumstances, we needed to make some changes for different reasons but that is the inconsistency we are showing the whole season. Three days ago; fantastic game, great performance and we deserved to go to the final and then today, we cannot use any words to describe this performance. It was not great, it was not good."
Asked if he felt let down by his players, Pochettino said: "No. There are too many details and circumstances why this happened. That is the experience we need to make sure the team doesn't have in the future. The club is building a new project, a new way to operate and of course, always that is a risk you need to take when you build a young squad, it takes some time with all the circumstances we are living.
"The circumstances are not helping to be more competitive, to be better, to be more consistent. That is the reason this type of game can happen when you play a team like this that in the last three or four years are preparing to win the Premier League, to fight for the big trophies."